Hoist for semitrailers



fie 3Q, 1936. H. w. HELMS HOIST FOR SEMITRAILERS 2 Sheets-Sheet 1Original Filed April 8, 1932 June 30, 1936. H HELMS 2,045,641

HOIST FOR SEMITRAILERS Original Filed April 8, 1932 2 Sheets-Sheet 2Patented a... 30, 1936 HOIST FOR SEMITRAILERS Harry W. Helms, Detroit,Micln, assignor to Highway Trailer Company, Edgerton, Wia, a corporationof Wisconsin Original application April 8, 1932, Serial No. 603,963.Divided and this application May 31, 1935, Serial No. 24,193

11 Claims. (Cl. 298-22) This application is a division of my applicationSerial No. 603,963, filed April 8, 1932, and the purpose of theinvention to which it'relates is to provide mechanism on the tractorvehicle adapted for tilting the body of a semi-trailer coupled theretoso as to dump the load from the trailer. An object of the invention isto utilize in connection with dumping or lifting mechanism a portion ofthe connection by which the semitrailer is attached to the tractorvehicle, but without lifting the heavier portions of the couplingdevice. The invention consists in the combination herein shown anddescribed, as indicated by the claims.

In the drawings:

Figure 1 is a partial side elevation of the tractor and semi-trailerembodying the hoisting and coupling mechanism of this invention.

Figure 2 is a plan view of the lower fifth wheel and coupling meansemployed in the structure of Figure 1.

Figure 3 is a vertical section taken as indicated at line 3-3 on Figure2.

Figure 4 is a vertical section on a larger scale than Figure 1, showingthe coupling connections of that structure.

Figure 5 is a detail view in side elevation indicating the operation ofthe coupler during the dumping action.

In the structure which is the subject of this invention, the mounting ofthe hoist or lifting mechanism on the tractor vehicle instead of on thechassis of a trailer permits of a simpler and cheaper construction forthe trailer itself, and allows the same hoisting mechanism to serveseveral trailers used interchangeably with a single tractor. It alsopermits the owner of a tractor to use it with an assortment of trailersdesigned for various purposes, among which assortment there may be onlyone trailer constructed with a dumping body. In my aforesaid applicationSerial No. 603,963 there is shown an arrangement in which the fifthwheel, by which the tractor and trailer are coupled, is mounted on ahoist mechanism so that the fifth wheel itself is lifted bodily fortilting the trailer body by raising its forward end. In the presentconstruction, however, I avoid lifting the heavier portions of the fifthwheel, namely, the lower element, consisting of the relatively largebearing area, and, instead, this area is made in two sections with aspace extending longitudinally between them to accommodate the upwardswing of a hoisting arm which engages with the pivot or king pinassociated with the upper plate of the fifth wheel and thus lifts thetrailer body when the dumping action is desired. The lower element ofthe fifth wheel is made, as shown in Figure 2, consisting of twoplatform portions, 3|], 30, having a rearwardly opening slot, 3|, toreceive the king pin for coupling, and having a forwardly opening slotor channel, 32, through which the outer end portions, 50, of thehoisting arms, may move vertically in engagement with the king pin, it,itself. Hydraulic hoisting cylinders are shown at l1 operativelyconnected at IS with lifting arms, 3, fulcrumed at 2 on the frame, I, ofthe motor truck.

The supporting tables, 3|), of the lower fifth wheel may be formed asintegral parts of the same casting, being joined by a deep channelportion, 3|, in which the outer ends, 50, of the lifting arms, 3, areaccommodated when the parts are in normal traveling position. The ends,50, of the arms are joined to a terminal, 5 l, carrying a pivot, 52,which supports a rockable socket member, 53, in which the king pin, 2|,of the trailer is lodged in coupled position. The pivot, 52, permits thesocket, 53, to change its angular relation to the lifting arms, 3, 3,when the hoist mechanism is operated to elevate the forward end of thetrailer chassis, 20, to which the king pin, 2|, and upper bearing plate,2 P, are permanently attached, and it also permits the rear end of thesocket to be depressed by collision of its inclined cam surface, 54,with the king pin, 2|, as the vehicles come together in the couplingoperation.

In coupled relation the king pin is retained in the socket by engagementof a forked arm or yoke, 55, which is pivotally attached to the socketmember, 53, at 56, so that it may swing vertically through a limitedrange with respect to the socket, 53. When the hoisting arm, 3, is atits lower limit, the yoke arm, 55, is held in horizontal position byengagement of its laterally extending lugs, 56 and 51, with the bottomsof notches or pockets, 58, in the sides of the channel, 3|. The yokeportion, 55, of the arm, 55, fits into the grooved or reduced portion,2|, of the king pin and thus serves to check the king pin against upwardmovement out of the socket when the vehicles are traveling, and at thesame time limits forward movement of the king pin, holding it captiveagainst the upstanding rear wall, 59, of the socket member, 53. Theterminal, 5|, of the hoisting arm, and the socket, 53, which it carries,

are yieldingly upheld in coupling position by means of a spring, 50,shown in Figure 4, attached to the under side of the hoisting arm andresting upon a rockable abutment, 6|, fulcrumed upon any suitablesupport associated with the vehicle frame. Thus when the king pinencounters the sloping cam surface, 54, it momentarily depresses thesocket, 53, and the end of the hoisting arm, but these parts arereturned to their upper limiting position, as shown in Figure 4, by theresiliency of the spring, 60. To permit uncoupling of the vehicles it isonly necessary to rock the abutment, 6|, into non-supporting positionwith respect to the spring, 60, as shown in Figure 4, so that theterminal, 5|, of the hoisting arm, and the socket, 53, may drop out ofengagement with the king pin, 2|, permitting the tractor to pull awayfrom the trailer. It will be understood that the temporary support, 22,will have been lowered into operative position, as shown in Figure 1,before the vehicles are thus separated.

As indicated in Figure 5, the socket member, 53, swings about its pivot,5|, when the hoisting arm elevates the trailer chassis, 20, and body todumping position. To forestall any possibility of the king pin, 2|,escaping from the socket while the body is thus tilted up at the forwardend, and the pivoted yoke arm, 55, is not checked against swinging aboutits pivot, 56, I provide a pair of hook-shaped extensions, 52, on theterminal, 5|, to engage laterally extending lugs, 63, on the yoke, 55.The change of angular relation between the socket, 53, and the terminal,5|, which occurs when the hoisting arm is lowered, carries the hooks,62, out of engagement with the lugs, 63, as seen in Figure 1.

I claim:

1. In combination, a tractor, a semi-trailer and a separable fifth wheelincluding a depending coupling member on the trailer and a platformmember on the tractor comprising a pair of laterally separated platformsurfaces spaced apart to receive the coupling member between them,together with a hoisting arm fulcrumed on the tractor with its liftingend normally disposed between said platform surfaces, and coupling meanscarried by said end of the hoisting arm engageable with the couplingmember of the trailer by relative horizontal movement of said parts withthe coupling member accommodated between said platform sections, wherebythe hoisting arm is adapted to lift the trailer from the platformsurfaces.

2. In the combination defined in claim 1, retaining means associatedwith said coupling means automatically adjusted when the hoisting memberis lifted to elevate the front end of the trailer into dumping position,for preventing vertical separation of the coupling member from thehoisting arm.

'3; In the combination definedin claim- 1, said coupling member on thetrailer being in the form of a depending king pin having a reducedportion, a member carried bythe hoisting arm and engageable with saidreduced portion of the king pin in the coupled relation of the parts,and sup plemental retaining means on the hoisting arm movable to engagea cooperating part of said member when the coupling end of the hoistingarm is elevated for lifting the front end of the trailer and tilting thelatter into dumping posi-- tion.

4. In combination, a tractor, a semi-trailer, a separable fifth wheelincluding a platform member fixed on the tractor and an upper bearingplate with a depending king pin on the trailer disengageably secured inswiveled relation to the platform, together with hoisting mechanism onthe tractor arranged to lift the front end of the trailer for tilting itinto dumping position, thereby separating said king pin and bearingplate from the platform, and retaining means arranged to preventseparation of the trailer from the hoisting member and shiftable intoeffective retaining position by the hoisting movement.

5. In combination, a tractor, a semi-trailer and a separable fifth wheelconnecting them, together with a hoisting arm mounted on the tractor formovement through the lower fifth wheel member and provided with'meansfor engagement with the upper member of the fifth wheel in such movementfor lifting the trailer from the supporting surface of the lower memberand tilting it, said upper member of the fifth wheel including adepending king pin having a reduced portion, means engageable with saidreduced portion of the king pin in the coupled relation of the fifthwheel parts, and supplemental retaining means carried by'the hoistingarm movable to engage a cooperating part of the upper fifth wheel memberincident to the lifting action of the hoisting arm in tilting thetrailer.

6. In combination, a tractor, a semi-trailer and a separable fifth wheelincluding a depending coupling member on the trailer, and a platformmember on the tractor comprising a pair of laterally separated platformsurfaces spaced apart to receive the coupling member between them,together with a hoisting arm fulcrumed on the tractor ahead of saidfifth wheel with its movable end disposed to pass between said platformsurfaces, whereby said arm is adapted to engage said depending couplingmember and lift the trailer.

'7. In the combination defined in claim 6, retaining means associatedwith said hoisting arm and automatically adjusted by the liftingmovement of said am for preventing vertical separation of said couplingmember from the hoisting arm.

8. In the combination defined in claim 6, a socket carried at the end ofsaid hoisting arm to engage the depending coupling member, withuniversal pivotal connections between the socket and the arm toaccommodate the change in angular relation between the hoisting arm andthe trailer in the lifting operation.

9. In the combination defined in claim 6, a socket secured to the end ofthe hoisting arm for engaging said depending coupling member, the rearend of said socket having an inclined cam surface, and the socket beingyieldingly depressible with respect to the arm to permit said couplingmember to ride over said cam surface in the coupling operation.

10. In the combination defined in claim 6, a socket secured to the endof the hoisting arm for engaging said depending coupling member,

the re'ar'end of said socket having an inclined cam surface, and thesocket being yieldingly depressible with respect to the arm to permitsaid coupling member to ride over said cam surface in the couplingoperation, together with means for lowering said socket at will torelease the coupling member.

11. In combination, a tractor, a semi-trailer, a separable fifth wheelincluding a platform member fixed on the tractor, and an upper bearingplate with a depending king pin on the trailer disengageably secured inswivelled relation to the platform, together with hoisting mechanism onthe tractor arranged to lift the front end of the trailer for tilting itinto dumping position, thereby separating said king pin and bearingplate from the platform, and retaining means actuated by the hoistingmember and shifted thereby into position to prevent separation of thetrailer from the hoisting member when the trailer is tilted.

HARRY W. HELMS.

